SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0ef79b83fb50fbb4442a01fcf81ed2605f76febb2cc97cf2beed56c49eb5a05' 
  AND token = 'KghlM1ETeabAqHFpRRqi6VV+vrey6kP81DAtcyiJJ3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}